2C-D (2,5-dimethoxy-4-methylphenethylamine, also known as 2C-M) is a psychedelic drug of the 2C family that is sometimes used as an entheogen. It was first synthesized in 1970 by a team from the Texas Research Institute of Mental Sciences, and its activity was subsequently investigated in humans by Alexander Shulgin. The full name of the chemical is 2,5-dimethoxy-4-methylphenethylamine. In his book PiHKAL (Phenethylamines i Have Known And Loved), Shulgin lists the dosage range as being from 20 to 60 mg and many people recommend higher doses. Lower doses (generally 10 mg or less) of 2C-D have been explored as a potential nootropic, albeit with mixed results. 2C-D is generally taken orally, though may be insufflated (i.e. taken nasally). Insufflating tends to cause intense pain, however, and the dosage level is usually much lower, typically in the region of 1 to 15 mg.